Pancreatitis in pregnancy has a prevalence of 1.5/1500-4500 cases, constituting one of the most common acute abdomen wedges, with biliary origin in 70% of cases, triglycerides in 20% and other causes in the remaining 10%, including choledochal cyst (CC) as a rare cause with three previous reports in literature, which may have a fatal outcome with fetal loss in some cases.We report the case of a 25-year-old patient with 30.4 weeks of gestation (WOG) that arrived to emergency room with right upper quadrant and epigastric pain for the last 8 hours, associated with nausea and vomiting. No pathological background referred. At physical examination with jaundice, gravidic abdomen for 30.4 WOG pregnant, fetal movements presents, Murphy (+) and epigastric pain on deep palpation. Laboratories report total bilirubin (TB) 3.9 mg/dl and direct bilirubin (DB) 3.69 mg/dl Alkaline phosphatase (AP) 2038 IU/L Amylase 280 IU/L Lipase 1938 IU/L. Pancreatitis is confirmed and abdominal ultrasound (US) is requested to determine biliar origin. USG reports gallbladder of 9×4 cm, thin walls without filling defects, dilated intrahepatic bile duct and common bile duct cyst. Cholangiopancreatography Resonance Imaging (CPMR) concludes Todani I choledochal cyst of 17×9 cm, with displacement of duodenum, colon and páncreas. Due to gestation ongoing appropriate medical management with fluids and analgesics was started until remission of pancreatitis 72 hours later. After delivery at 34 WOG, cholecystectomy was performed with hepático-jejunum Roux-Y anastomosis successfully. Histopathologic analisis reports inespecific inflammation without displasia or metaplasia. At four months follow-up patient is asymptomatic.Pancreatitis in pregnancy is a common cause of acute abdomen, rarely associated with choledochal cysts as the cause. Surgical resolution once pregnancy is over must be done as soon as possible by the high risk of adenocarcinoma degeneration and recurrent pancreatitis.